The present invention generally relates to communication systems that receive differential signals from a serial host, and in particular to a circuit for providing power to the serial device and termination of differential signals received therefrom.
Buses are widely used to provide unidirectional or bidirectional communication between two or more electronic devices. For example, a bus may be utilized to connect a printer, a monitor, and a keyboard with a CPU (Computer Processing Unit).
In order to communicate between components, electrical signals are applied to the bus by a transmitting station and received by another station on the bus. For high speed serial communications, a xe2x80x9cdifferentialxe2x80x9d type of signal transmission has been found particularly advantageous. A differential signal is transmitted over a pair of wires. Each wire transmits the same signal, but with different polarities. A differential signal provides a higher signal to noise ratio and better overall performance because, in part, timing distortions are minimized.
However, there is a need for a connector port that, along with terminating the differential signals, provides RFI filtering and electrostatic discharge protection for the bus. Moreover, because many types of serial devices require the connector port to supply power, there is a need to regulate the amount of power provided for preventing damage to various devices or wiring due to a fault that causes an inordinate amount of current to be drawn.
The present invention provides a connector port having a data interface circuit and a power interface circuit. The data interface is operably connected between an input differential wire pair and an output differential wire pair for providing termination of the input wire pair and transmission of signals onto the output wire pair. Further, the power interface includes a fuse link operably connected between a voltage input and a voltage output for providing overcurrent protection.
To this end, in an embodiment, a connector port for connecting to a serial device providing a differential wire pair input signal is provided. The port comprises a data interface circuit operably connected to the serial device for providing termination of the input signal and responsive differential output signals onto an output wire pair, and a power interface circuit having a voltage output operably connected to the serial device and a fuse link attached to the voltage output for providing overcurrent protection.
In an embodiment, the interface circuit further includes electrostatic discharge protection operably connected to the differential wire pair input signal.
In a further embodiment, the interface circuit further includes a filter operably connected to the differential wire pair signal.
In an embodiment, the power interface further includes a switch operably connected to the voltage output for substantially removing power from the serial device.
In a further embodiment, the power interface further includes a current sensor operably connected to the switch for detecting the amount of power received by the serial device.
In an embodiment, a connector jack is provided for containing the data interface circuit and the power interface circuit.
Additional advantages and features of the present invention will become apparent upon reading the following detailed description of the presently preferred embodiments and appended claims, and upon reference to the attached drawings.